The invention relates in general to measuring devices and in particular to devices for measuring the elevation and azimuth of a tube, such as a gun tube.
Verifying the pointing accuracy of an artillery cannon, mortar tube, or other equipment in an engineering environment has been and continues to be a problem. A theodolite has been used to measure the azimuth of an artillery cannon, mortar tube, or other equipment. U.S. Pat. No. 5,225,626 issued on Jul. 6, 1993 to Bowers discloses another arrangement for measuring the azimuth of a tube.
Shortcomings of these approaches are the inability to quantify or calibrate the apparatus and to establish or remove bias from the measurement. Additionally, the use of a single optical instrument, such as a theodolite, to align to a projection of a tube axis is a subjective process and highly dependent upon the skill of the theodolite operator. Further, the prior devices may measure azimuth, but not elevation angle.